1. Field of the Invention
The present invention relates to a self-propelled insertion device.
2. Description of the Related Art
In general, the insertion device of an endoscope or the like is inserted into a body cavity. As this type of insertion device, a self-propelled insertion device known in the art, in which a rotating body serving as an insertion assisting tool is provided for an insertion section, for example. In this type of insertion device, the rotating body is rotated to generate a propulsion force with which the insertion section is advanced or retreated, and the operator's operation of inserting the insertion section is assisted thereby. An insertion device provided with this type of insertion assisting tool is propose, for example, in Jpn. Pat. Appln. KOKAI Publication No. 2014-004268.
Where an insertion section is inserted into a body portion having complicated flexures, like the large intestine, the insertion section bends more when it is inserted into a deeper portion, and the insertion force applied from the proximal portion may not be transmitted to the distal end. To solve this problem, for example, Jpn. Pat. Appln. KOKAI Publication No. 2004-188217 discloses a mechanism for increasing the stiffness of an insertion section. Since the bend of the insertion section is corrected thereby, easy insertion of the insertion section is assisted.